Our very broad aims are to study the molecular, kinetic and mechanistic properties of PDH. Our more specific objectives are: 1. To delineate the nature of the active site of PDH by the kinetic study of inhibitors and substrates. 2. To study the chemical mechanism of PDH. 3. To synthesize inhibitors including irreversible inhibitors that may be candidates for practical use. 4. To develop a good and general purification procedure based upon affinity chromatography. 5. To develop a new substrate that can be used in a continuous chromogenic assay with a spectrophotometer and recorder. 6. To develop a new substrate that can be used as an activity stain for detecting PDH in gel electrophoresis. 7. To study the molecular properties of PDH. 8. To study other kinetic phenomena.